Alumina vs. Silicon Carbide
Alumina belongs to the oxide-based engineering ceramics classification, while silicon carbide belongs to the non-oxide engineering ceramics. There are 20 material properties with values for both materials. Properties with values for just one material (6, in this case) are not shown.
For each property being compared, the top bar is alumina and the bottom bar is silicon carbide.
Metric UnitsUS Customary Units
Mechanical Properties
| Compressive (Crushing) Strength, MPa | 1920 to 2750 | |
| 2780 to 3900 |
| Elastic (Young's, Tensile) Modulus, GPa | 220 to 370 | |
| 370 to 490 |
| Flexural Strength, MPa | 260 to 430 | |
| 410 to 600 |
| Fracture Toughness, MPa-m1/2 | 3.7 to 7.2 | |
| 3.4 to 4.6 |
| Knoop Hardness | 960 to 1660 | |
| 2500 to 2900 |
| Poisson's Ratio | 0.22 to 0.24 | |
| 0.14 to 0.21 |
| Tensile Strength: Ultimate (UTS), MPa | 210 to 290 | |
| 210 to 370 |
Thermal Properties
| Maximum Temperature: Mechanical, °C | 650 to 1730 | |
| 500 to 1590 |
| Maximum Thermal Shock, °C | 200 to 300 | |
| 210 to 660 |
| Specific Heat Capacity, J/kg-K | 870 to 940 | |
| 670 to 1180 |
| Thermal Conductivity, W/m-K | 14 to 30 | |
| 120 to 170 |
| Thermal Expansion, µm/m-K | 6.7 to 8.2 | |
| 4.0 to 4.5 |
Electrical Properties
| Electrical Resistivity Order of Magnitude, 10x Ω-m | 6.2 to 14 | |
| 0.94 to 3.3 |
Otherwise Unclassified Properties
| Density, g/cm3 | 3.4 to 4.1 | |
| 3.0 to 3.2 |
Common Calculations
| Stiffness to Weight: Axial, points | 35 to 53 | |
| 69 to 84 |
| Stiffness to Weight: Bending, points | 57 to 62 | |
| 79 to 82 |
| Strength to Weight: Axial, points | 14 to 23 | |
| 18 to 34 |
| Strength to Weight: Bending, points | 19 to 28 | |
| 24 to 38 |
| Thermal Diffusivity, mm2/s | 3.7 to 10 | |
| 38 to 79 |
| Thermal Shock Resistance, points | 4.9 to 14 | |
| 6.9 to 18 |